SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28291da24fc9c90da7e3e6b35adc5850a33c79e7b69af4ceee7a087918323d82' 
  AND token = 'JVWyGuhV4B3BwqCak9PKESI2moaJf6Wxd/hoSI+CSkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}